Apparatus for recording and repeating telephonic speech.



Patnted hot. 22, lam;

H. A. RHODES. APPARATUS FOR RECORDING AN D. REPEATING TELEPHONIG SPEECH.

(Application filed In; 2. 1900.)

(In lodql.

2 Sheets-Shaut 2.

HG. 5. I

[N VEN TOR. Harr A Rhodes,

UNITED STATES FAT-ENT Orrrcn.

HARRY AfRHoDEs, or DENVER, COLORADO;

APPARATUS FOR RECORDING AND REPEATING T ELEPHONlC SPEECH.

SPECIFICATION formingpart of Letters Patent No. es aase, dated batter 22, 1901. Application filed January 2,1900. Serial No. 147. (No model.)

new and useful Improvements in Apparatus for Recording and Repeating Telephonic Speech or Sounds; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

My invention relates to an apparatus for recording and repeating telephonic speech or sounds. When speech is transmitted by telephonic instruments and methods through telephone-circuits, it is wellknown that the wires or circuits and attendant fields absorb a portion of the energy of the speech or current waves,said absorption varying in amount in accordance with the length, character, and

specific construction of the circuit, but amounting to practical extinction of such current or speech wave when thewires and circuits are sufficiently extended. This limit is commercially reached in many cases at distances varying from three to five hundred miles where standard No. 10 copper wire is used. Hence unless a district is densely populated it is financially impracticable to construct and maintain the requisite enlarged wires or circuits for the direct transmission of articulate speech beyond said distances. The income will not justify the expense. Other considerations being equal, absorption or diminution of current or speech energy is proportional to the length of the circuit or line wires. It is therefore highly desirable that means shall be provided whereby the original energy or speech-wave current shall at any desired predetermined point in the circuit be reinforced, augmented, or strengthened by adding thereto a quantity of energy in the proper form, which said quantity of energy shall be at least equal to that lost by the speech wave or current while traversing the previous section or division of the circuit. It is obvious that this additional energy must be supplied from a source foreign or extraneous to or aside from that contained in the arriving current or wave, but nevertheless controlled and actuated by it to a sufficient extent to impart its phase or time form to the quantity of the energy added-thereto.

The objects of my invention are to provide means whereby an accurate record or copy of telephonic speech or sound Waves shall be automatically registered by the device or instrument transmittingv such telephonic speech-waves, such record or copy to be capable of reproducing by means of a transmitting device accurate copies of the original electric or telephonic waves or speech inelectric or telephonic circuits or sound-waves in air or other sound-conducting media, as may be desired; to provide means of receiving telephonic messages at any suitable predetermined point in or upon the circuit; to provide means for imparting additional energy to or of amplifying the speech-waves so received; to provide means for automatically repeating such telephonic speech-waves into or upon secondary, auxiliary, or additional telephonic circuits for the purposeof transmitting said speech-waves through such circuits, and to provide means of reproducing telephonic speech-waves in air or other soundconducting media.

I accomplish the foregoing objects by the use of the mechanism illustrated in the accompanying drawings, in which- Figure 1 is a diagrammatic view illustrating my improved apparatus and showing the circuits. Fig. 2 is a top or plan view of the cylinder and the recording and reproducing instruments. Fig. 3 is a section taken through the same. Figs. 4 and 5 are face views of the recording and reproducing instruments, respectively.

Similar reference characters indicating corresponding parts in these views, let the reference characters A, A A and A designate standard induction-coils Well known in telephonic construction. As shown in the drawings, the primaries of each set of two are connected in multiple.

B B designate sources of current-supply.

T T are telephone-transmitters of suitable construction.

R R are recording instruments, each consisting of an iron core, upon-which two cir-- cuit-wires are wound, insulated from the iron core and from each other and wound differentially or capable of being so connected. These helices, which I shall call recorders, are suitably disposed to act magnetically upon a lever R connected with a plate R hinged at R or other device carrying a cutting or recording tool R, engaging with the surface of the repeating-cylinder 5. The transmitters T and T are each combined with a suitable tracing-tool T a lever T, and a plate T hinged at T, or other suitable connecting devices for transferring the record from the repeating-cylinder to the microphone or transmitter.

S S are shunts of high resistance compared with the primary circuit of the inductioneoil. The outer surface of the repeating-cylinder 5 is constructed of wax or other material capable of receiving and retaining an impression from the recording-tool. The cylinder has a uniform revolution about its axis.

I am aware that the individual instruments herein described are well known, and Itherefore do not claim their invention.

From Y a metallic telephone-circuit proceeds to the secondary circuit of the induction-coilA', and thence by the circuit X to one of the circuits of the recorder R. Telephonic impulses, traversing circuit X, cause the recorder R to actuate the recording-tool at R, causing the tool to vary the depth of the cut or groove on the recordingface of the cylinder in exact accordance or conformity with the extent and form of the current variations in circuit X. The tracing-tool T being normally in contact with the groove is now actuated by impinging upon the record or variations of depth in the groove as the record by reason of the revolution of the cylinder passes under the tracing-tool. It is obvious, how ever, that the same result may be accomplished if the record-surface be made stationary and the tracing-tool movable. By suitable arrangements the pressure of the tracing-tool upon the record may be controlled. The motion of the tracing-tool due to the record is now transferred to the microphone by means of the multiplying-lever T having the longer arm connected with a microphone T By the principle of the lever the amplitude or degree of motion of the tracing-tool is multiplied according to the ratio between the long and the short arm of the lever. The extra power required to maintain this augmented amplitude against the mechanical resistance of the microphone-contact is furnished by the extraneous power employed to drive the cylinder. The motion of the tracing-tool being thus augmented and amplified .is by the agency of the lever impressed upon the microphone, thus causing proportionate variations of current strength to traverse the circuit 13* A A* primary and shunt S As the primaries A A are each of very low resistance and, furthermore, are connected in multiple, they practically shortcircuit the shunt S and very little of the battery-current traverses this shunt, it being of from one to four ohms resistance and made adjustable. To recapitulate, the telephonic impulses, of whatever character, traversing the circuit X are first transformed into magnetic impulses in recorder R, actuating the recording-tool R The recording tool impresses the form and amplitude of these in1- pulses upon the surface of the revolving cylinder, which conveys them to the tracing-tool T The tracing-tool transfers the form with multiplied amplitude and extra force by means of the lever T" tothe microphone T whence by the battery and coil they proceed to circuit N. As the cylinder parts engaged by the two sets of tools R and T are not in the same plane upon the cylinder, nor even necessarily upon the same cylinder, telephonic impulses may be sent from the circuit N by way of circuit X, recorder R its corresponding lever R and tool R to the cylinder, and thence by way of tool T, lever T and microphone T to the coils A A and to circuit Y. It is obvious that telephonic impulses generated in the secondary of A for N will arrive by Way of X at recorder R To prevent a repetition of the record here, I have arranged the secondary of A by way of N differentially at R to annul the effect of X. Now to prevent the differential N from operating by impulses proceeding from N by way of A A, I have by-circuited the primaries of A A by a shunt S This effectually prevents induction to N and makes a retarding or choke coil of A A operating to force the impulses proceeding from N into the recording-circuit X. Then properly proportioned to the primary induction coil, the shunt S does not materially effect the transmission to N from T or Y. On the opposite or Y side the shunt S and circuit X serve the same purpose as does shunt S and circuit N on the N side, and the system is thus successfully duplexed.

In the drawings a cylinder is shown; but I do not confine my invention to the use of the cylinder, as it is obvious that the flat plate or other uniform surface may be used to receive the record. Again, I do not confine myself to the use of the particular lever devices shown in the drawings, as it is obvious that other agencies-such as air, gas, or liquids, suitably inclosed in tubes or chambers-may be made to act to transfer the amplified record to and from the cylinder. Again, the record is not destroyed by the act of reproducing the electric or sound waves, and may by the use of the tracing-tool and levers (or other conductor) be transferred to any sonorous diaphragm, and so cause a copy of the original sound-waves to be reproduced in air. This feature is of value where the record may be required as evidence in court, for instance. The arrangements of induction-coils A A A A shown in the drawings is the one I prefer, but the two second ary circuits, as shown at A A or A A may be Wound upon one primary core and winding.

Each pair of instruments, composed of a recorder and a transmitter, is attached to a supporting frame or yoke 6, movably mounted on a bar 7, attached to the frame 8, in which the cylinder 5 -is journaled. The cylinder may be rotated by connecting a pulley 9, fast on the cylinder shaft, with a motor (not shown) in the same manner as a phonographcylinder is operated.

It must be understood that a plurality of tracing or reproducing tools may be employed simultaneously, (or nearly so,) each and all operating upon one electric transmitter or upon several electric transmitters, whence the respective telephonic impulses generated thereby may be added or summated upon one circuit by providing the necessary lead-wires from each electric transmitter to said circuit, thus further augmenting the speech-waves in a manner similar and equivalent to the summation of two similar wavesounds in air.

As shown in the drawings, (see Fig. 2,) the two sets of instruments R T and R T are mounted on a sleeve 7, longitudinally and revolubly movable on the shaft or bar 7. To this sleeve 7 is also attached an arm 10, whose free extremity is threaded to engage the threaded part of the cylinder-shaft 12,

whereby as the cylinder and the said shaft are rotated the sleeve '7 and its connections are made to travel in the direction indicated by the arrow in Fig. 2 or in the opposite direction, according to the direction of the cylinders' rotation.

The movementpermitted by the construe tion shown in Fig. 2'is very limited and is only intended to illustrate the principle.

Having thus described my invention, what I claim is 1. The combination of a shunt-circuit, a microphone and battery circuit connected in multiple with a primary inductive circuit whereby the primary inductive circuit is short-circuited by the combined shunt and battery circuit.

2. In a telephone recorder and repeater, the combination of a movable record-surface, an electromagnetically-actuated recording-tool adapted to engage said surface, a repeatingtool also adapted to engage the record-surface, a microphone or transmitter, and a connection between the repeatingtool and the microphone whereby the amplitude of the recorded sound-waves is augmented in the transmitting-circuit.

3. In a duplex telephone, recorder and repeater, the combination of two recording instruments, arranged to be active and idle alternately, two repeating instruments, and two secondary electrical circuits, arranged to act simultaneously and differentially upon the magnet-core of the idle recording instrument.

4. In a duplex telephone, recorder and re peater, the combination of two recording in struments, two repeating instruments and two secondary electrical circuits arranged to act simultaneously and differentially upon the magnet-core of the idle recording instrument, and means for short-circuiting one of the secondary circuits when the said inactive recording instrument becomes the active recording instrument of the duplex system.

5. In a duplex telephone, recorder and re peater, the combination of a recording-surface, two recording instruments, two repeating instruments, and four secondary electric induction-circuits arranged in sets of two, each set being in juxtaposition to and adapted to act simultaneously by reciprocal electric induction upon or within two primary electrical circuits connected in multiple.

6. In a duplex telephone, recorder and repeater, the combination of two recording instruments, two repeating instruments, a primary electrical induction-circuit for each set composed of a recording and a repeating instrument, two secondary circuits associated with each primary circuit, the said secondary circuits being arranged to annul the otherwise normal eflect of each upon, and thus render idle, one of the recording instruments.

-7. In a duplex telephone, recorder and repeater, the combination of two recording instruments, two repeating instruments, a primary electrical induction-circuit for each set composed of a recording and a repeating instrument, two secondary circuits associated with each primary circuit, the said secondary circuits being arranged to annul the otherwise normal effect of each upon, and thus render idle one of the recording instruments,- and a shunt connected in multiple with each primary circuit and with the battery and microphone circuit, whereby the primary circuit is short-circuited, induction to one of the secondary circuits prevented, and the telephonic impulses made to pass directly from the main line through one of the secondary circuits to the previously idle but now active recording instrument.

8. In a duplex telephone, recorder and repeater, the combination of two recording instruments, two repeating instruments, a primary circuit, two secondary circuits associated with said primary circuit and arranged to annul the otherwise normal effect of each upon, and thus render idle a recording instrument, and a shunt connected in multiple with the primary circuit whereby the latter is shortcircuited and induction to one of the secondary circuits prevented when the previously idle recording instrument becomes the active recording instrument of the duplex system.

9. In a duplex telephone, recorder and repeater, the combination of two recording instruments, two repeating instruments, a primary circuit, two secondary circuits associated with said primary circuit and arranged to annul the otherwise normal effect of each upon, and thus render idle, a recording in strument and a shunt ofhigher resistance than the primary circuit but of lower resistance than one of the secondary circuits, said shunt being connected in multiple with the primary circuit whereby the latter is short-circuited and induction to one of the secondary circuits prevented, whereby the previously idle recording instrument becomes the active recording instrument of the duplex system. M 10. In a duplex telephone, recorder and repeater, the combination of two recording in.- struments, two repeating instruments, a primary circuit, two secondary circuits associated with said primary circuit and arranged to annul the otherwise normal effect of each upon, and thus render idle, one of the recording instruments, and a shunt connected in multiple with the primary circuit and with the battery and microphone circuit, whereby the latter is short-circuited and induction to one of the secondary circuits prevented, thus making the previously idle recording instrument, the active recording instrument of the duplex system.

11. In a duplex telephone, recorder and repeater, the combination of two recording instruments, two repeating instruments, two primary electrical induction-circuits for each set composed of a recordinginstrument-and a repeating instrument, the primary circuits being connected in multiple, two secondary circuits associated with each two multipleconnected primarycircuits, the secondary circuits being arranged to annul the otherwise normal effect of each upon, and thus render idle, one of the recording instruments, and a shunt connected in multiple with each two multiple-connected primary ci1'cuits,whe1'eby the latter are short-circuited, induction to one of the secondary circuits prevented, and the telephonic impulses made to pass directly from the main line through one of the secondary circuits to the previously idle but now active recording instrument.

In testimony whereof I aflix my signature in presence of two witnesses.

HARRY A. RHODES Witnesses:

GRACE MYTINGER, A. J. OBRIEN. 

